scholarly journals Operation Characteristics of Bypass Diode for PV Module

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2416 ◽  
Author(s):  
Woo Shin ◽  
Suk Ko ◽  
Hyung Song ◽  
Young Ju ◽  
Hye Hwang ◽  
...  

Bypass diodes have been widely utilized in crystalline silicon (c-Si) photovoltaic (PV) modules to maximize the output of a PV module array under partially shaded conditions. A Schottky diode is used as the bypass diode in c-Si PV modules due to its low operating voltage. In this work, we systematically investigated the origin of bypass diode faults in c-Si PV modules operated outdoors. The temperature of the inner junction box where the bypass diode is installed increases as the ambient temperature increases. Its temperature rises to over 70 °C on sunny days in summer. As the temperature of the junction box increases from 25 to 70 °C, the leakage current increases up to 35 times under a reverse voltage of 15 V. As a result of the high leakage current of the bypass diode at high temperature, melt down of the junction barrier between the metal and semiconductor has been observed in damaged diodes collected from abnormally functioning PV modules. Thus, it is believed that the constant leakage current applied to the junction caused the melting of the junction, thereby resulting in a failure of both the bypass diode and the c-Si PV module.


2016 ◽  
Vol 36 (5) ◽  
pp. 63-71
Author(s):  
Woogyun Shin ◽  
Seokhwan Go ◽  
Youngchul Ju ◽  
Hyosik Chang ◽  
Gihwan Kang
Keyword(s):  

2016 ◽  
Vol 36 (4) ◽  
pp. 41-47 ◽  
Author(s):  
Suk-Whan Ko ◽  
Young-Chul Ju ◽  
Jung-Hun So ◽  
Hye-Mi Hwang ◽  
Young-Seok Jung ◽  
...  

2019 ◽  
Vol 9 (15) ◽  
pp. 3038 ◽  
Author(s):  
Germán Álvarez-Tey ◽  
José Antonio Clavijo-Blanco ◽  
Álvaro Gil-García ◽  
Rafael Jiménez-Castañeda ◽  
Carmen García-López

The shadow effect caused by nearby objects or the lack of cleaning significantly affects the performance of photovoltaics (PV) installations. This article analyses the bypass diode electrical behaviour and the thermal response of a PV crystalline module under shading or soiling conditions. PV cells of different substrings were covered progressively to simulate the effect of shading or soiling while a programmable electronic DC load was connected to a PV module to set an operating voltage. Three different tests were made to different PV crystalline technology. The paper characterizes in real conditions the I–V curve, bypass diode current, and front and back side PV cell temperature with contact sensor and infrared (IR) thermography, respectively. The results showed that the operation voltage established in the PV module defines the electrical bypass diode current and thermal response under normal operating conditions, shading or soiling. To show the bypass diode behaviour in such conditions, I–V curves were obtained, pointing out the value of the current that flows through bypass diodes in the whole voltage range.


2021 ◽  
Author(s):  
Rakeshkumar Mahto ◽  
Reshma John

A Photovoltaic (PV) cell is a device that converts sunlight or incident light into direct current (DC) based electricity. Among other forms of renewable energy, PV-based power sources are considered a cleaner form of energy generation. Due to lower prices and increased efficiency, they have become much more popular than any other renewable energy source. In a PV module, PV cells are connected in a series and parallel configuration, depending on the voltage and current rating, respectively. Hence, PV modules tend to have a fixed topology. However, in the case of partial shading, mismatching or failure of a single PV cell can lead to many anomalies in a PV module’s functioning. If proper attention is not given, it can lead to the forward biasing of healthy PV cells in the module, causing them to consume the electricity instead of producing it, hence reducing the PV module’s overall efficiency. Hence, to further the PV module research, it is essential to have an approximate way to model them. Doing so allows for understanding the design’s pros and cons before deploying the PV module-based power system in the field. In the last decade, many mathematical models for PV cell simulation and modeling techniques have been proposed. The most popular among all the techniques are diode based PV modeling. In this book chapter, the author will present a double diode based PV cell modeling. Later, the PV module modeling will be presented using these techniques that incorporate mismatch, partial shading, and open/short fault. The partial shading and mismatch are reduced by incorporating a bypass diode along with a group of four PV cells. The mathematical model for showing the effectiveness of bypass diode with PV cells in reducing partial shading effect will also be presented. Additionally, in recent times besides fixed topology of series–parallel, Total Cross-Tied (TCT), Bridge Link (BL), and Honey-Comb (H-C) have shown a better capability in dealing with partial shading and mismatch. The book chapter will also cover PV module modeling using TCT, BL, and H-C in detail.


2019 ◽  
Vol 39 (6) ◽  
pp. 15-25
Author(s):  
Chung-Geun Lee ◽  
Woo-Gyun Shin ◽  
Jong Rok Lim ◽  
Hye-Mi Hwang ◽  
oung-Chul Ju ◽  
...  

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